1. Field of the Invention
Thin layer chromatography is a versatile and economic method for the determination of a wide variety of drugs in physiological media. The field of thin layer chromatography has been extensively researched and many techniques and reagents have been developed for the detection of drugs. One such technique is exemplified in U.S. Pat. No. 3,714,035. This technique involves the scoring of the chromatograph adjacent one end to leave a plurality of openings in which discs may be introduced. One disc is impregnated with the analyte. In the other scored areas, one or more discs are introduced which have known amounts of specific drugs. By developing the sample and standards simultaneously on the same chromatograph, one can compare the migration rate of the sample spots to those of the standard spots, as well as their response to heat and/or chemical treatment. An accurate determination of whether or not a specific drug is present may thus be made.
However, in the course of the development of the chromatogram which may take anywhere from five minutes to well over an hour, it is essential to monitor the solvent front from time to time to determine if the chromatograms have developed sufficiently for the samples to be detected and identified as well as to prevent the solvent front from being eluted off the chromatographic plate. Current methods used for the purpose require the utilization of special or highly sophisticated equipment and/or sophisticated detection methods, as solvent fronts are usually very difficult to detect and follow visually. The method described herein provides for a visual monitoring of solvent fronts in thin layer chromatograph process whereby expensive and sometimes tedious detection systems and sophisticated technological know-how are eliminated.
2. Description of the Prior Art
Articles and texts of interest include Dole, et al. Detection of Narcotic Drugs, Tranquilizers, Amphetamines, Barbiturates in Europe, JAMA, 198, 349 (1966); Jones, et al. Drug Detection by TLC, Comparative Study, California Association of Criminologists, Menlo Park, California October 1973; Jones, et al. An Improved Method for the Detection of Phenothiazines, Annual Meeting, CAP-ASCP, Chicago, Illinois October, 1973; Davidow, et al. A Thin Layer Chromatographic Screening Procedure for Detecting Drug Abuse, The American Journal of Clinical Pathology, 38, 714 (1968). U.S. Pat. Nos. 3,914,174 and 3,496,102.